Walter h



Nov. 18, 1924.

W. H. COTTON DRAFT GEAR Filed Sept. 17. 1923 5 ShQQtI-Shi! l Nov. 18,1924.

w. H. COTTON DRAFT GEAR 3 Shoots-Sheet 2 Filed Sept.

Nov, 18, 1924.

W. H. COTTON DRAFT GEAR Filed Sept. 17, 1923 3 ws www N w s WIW;HMWIIIL@ JM uw m 9N f will i \HHHM W\ QN Patented Nov. 18, 1924.

UNITED STATES PATENT OFFICE..

WALTER H. COTTON, OIF CHICAGO, ILLINOIS, VASSDGrliTOJEt TO UNION :DRAFTGEAR GO., A CORPORATION OF ILLINIS.

DRAFT GEAR.

Application led September 17, 1923.

To c/,ZZ -wim t may concern.'

Be it known that I, Tarrina H. Co'r'rorr, a citizen of the UnitedStates, and resident of Chicago, county of Cook, and State of Illinois,have invented certain new and useful lmprovements in Draft Gears, ofwhich the following is a specification, and which are illustrated in theaccompanying drawings, forming a part thereof.

The invention relates to draft gears or shock absorbing devices forrailway cars, its object being to secure high efficiency and smoothnessof action both in compression and release.

A preferred embodiment of the invention is hereinafter described, and isillustrated in the accompanying drawings, in which- Fig. 1 is a centralplan section through the gear and tail strap of the coupler, details ofthe coupler and draft sills of a car being shown in plan;

Fig. 2 is a similar view, the gear being under compression in bufling;

Figs. 3 and 4l are vertical sections on the lines SH3 and 1 -4,respectively, of Fig. 1.

At 10, 10, there is represented a pair of center or draft sills of ayrailway car, of any preferred construction; at 11, 11, a pair of draftlugs, and at 12, 12,- a pair of builing lugs, attached to the sills inany pre ferred manner. The butt end of a coupler is represented at 13,and its extension, yoke or tail strap for encircling the gear is shownat 14.

The improved gear comprises a pair of chambered followers 15. 16,cooperating, respectively, with the draft and buiting lugs, the side andtop and bottom walls of these followers being of such length that thoseof the one will make contact with those of the other when the gear isfully compressed, serving to prevent over-compression and consequentinjury ofthe springs.

The end wall of each of the followers is apertured to loosely receive awedge-block 17, 18, the former being seated against the butt end of thecoupler and the latter against the rear cross member of the yoke. Theinner portions of the side faces of the blocks 17, 18, incline inwardlyto give these blocks the wedge form. Each of these wedge-blockscooperates with wedging faces on a pair of friction shoes 19, 20, and21, 22, the outer faces of which are parallel with the axis of the gear.A pair of. helical Serial No. 563,082.

springs 23, react between instanding shoulders on the friction shoes,spring seats 25, 26, being interposed between the springs and suchshoulders. Preferably the shoulders are slightly inclined to the axis ofthc gear, and the cooperating faces of the spring seats are given acomplementary form. l

A group of intercalating friction plates is interposed between the twofriction shoes on each side of the gear and the adjacent side walls ofthe followers. lCach of these groups comprises a set of plates 27, whichnormally extends from a short distance from the inner face of the endwall of the follower 15 and terminates a short distance within thecasing of the follower 16; and a set. of plates 28 which normally extendfrom a short distance from the inner surface of the end wall of thefollower 16 to a short distance within the casing of the follower 15.

Bars 29, 30, entend, respectively, through the wedge-block 17, thefriction shoes 19, 20, the plates 27 of both groups of friction plates,the side walls of the follower 15, and through the sills 10, 10; andthrough the wedge-block 18, the friction shoes 21, 22, the plates 28 ofboth groups of friction plates, the side walls of the follower' 16, andthe sills 10, 10. All of the named elements through which these barspass are suitably slotted to accommodate them, and, with the exceptionof the blocks 17, 18, such slots are of greater length than the width ofthe bars to permit relative movement with respect thereto.

Helical springs 31, 82, react, respectively, between adjacent ends ofthe bars 29, 30, being` seated against seats 33, 84, attached thereto.

The gear as described can, if desired, be assembled at the time ofinstallation. Vhen applied to a car the parts normally occupy theposition as shown in Fig. 1, the wedgeblocks 17, 18, projecting a shortdistance beyond the outer faces of the end walls of the two followersand bearing, respectively, against the coupler butt and the cross memberof the tail strap. Both of the last` named members are spaced a shortdistance from the adjacent follower. The ends yof the friction plates 27are lout of Contact with the inner face` of the `follower 15, and the.ends of the frictior'i vplates 28 are out of contact with the innerface of the follower 16. Both sets of plates touch at the outer ends oftheir slots the bar 29, 30, which passes through them. These two barsare at the outer ends of the slots in the side walls of the 'followersthrough which they pass. All of the springs are under slight tension.

Under the influence of bufling stresses the wedge-block 17 is carriedbackward with the coupler 13, and with it moves the bar 29, moving it tothe inner ends of the slots in the side walls of the follower, which areof greater length than the width of the bar. The wedge-block has aspreading action on the friction shoes 19, 20, and tends to move theminwardly, this movement, however, being resisted by the springs 23, 24.Iressure transmitted through these springs tends to* move the frictionshoes 21, 22, backwardly, this action, however, being resisted by thewedge-block 18, which spreads the shoes. The'spreading of the shoescompresses the two groups of friction plates against the side walls ofthe followers. When the end wall of the follower 15 engages the plates27, it moves them forwardly between the plates 28, the latter, however,first moving into contact with the end wall of the follower 16. Thesprings 31, 32, are compressed as the bar 29 moves inwardly.

If the force applied be sufficient the gear is finally compressed untilthe parts occupy the position shown in Fig. 2, further compression beingprevented by the contact of the inner end of the follower 15 with thefollower 16. Upon relief of the stresses which have caused thecompression of the gear, the latter is restored to the position of Fig.1, under the influence of the several springs. The wedge block 17 isfirst moved backward, relieving the outward pressure on the frictionplates and permitting the shoes 19, 20 to recede. The bar 29 coming intoengagement with the outer ends of the slots in the side walls of thefollower carries this element back, and presently engaging the shoulderson the plates 27 carries back these elements. The plates 23 movebackwardly under the influence of friction until their shouldersencounter the bar 30. As the springs 23, 24C expand pressure on theshoes 21, 22 is relieved, permitting them to recede from the wedge block18.

Under the influence. of draft stressesthe action is the same as in buff,but in the opposite direction.

As the gear is compressed in either direction its resistance, due bothto the springs and friction, is initially but slight and is graduallydeveloped. As a consequence the light compressive forces applied ineither direction are cushioned and the heavier shocks are substantiallyall absorbed. The release being effected by the springs 32, 33,

which ma?,7 be very heavy, is certain but is suitably retarded, to avoidshock, by the follow up of the friction shoes under the influence of thesprings 23, 24.

llhile the form and arrangement of the various elements of the gear asshown are preferred, both may be deviated fromY within the scope of theinvention.

I claim as my invention- 1. In a draft gear, in combination, a pair ofchambered followers, wedging elements in each follower adapted todevelop outward lateral pressure, groups of intercala-ting frictionplates interposed between such wedging elements and friction surfacesassociated with the side walls of the followers, bars extendingtransversely through the followers, and springs interposed between theouter end portions of the bars.

2. In a draft gear, in combination, a pair of chambered followers, acentral two-faced wedge associated with Veach follower, friction shoeshaving wedging faces cooperating with each face of each wedge, a groupof intercalating friction plates interposed between the shoes at eachside of the gear and a friction surface associated with the side wallsof the followers, a bar extending` transversely through each follower,Aand springs interposed between the projecting end portions of the bars.

3. In a draft gear, in combination, a pair of chambered followers eachhaving an aperture in its transverse wall, a central twofacedwedge-block projecting through eachV aperture and engageable directly bya coupler, friction shoes having wedging faces cooperating with eachface of each wedge, a group of intercalating friction plates interposedbetween the shoes at each side of the gear and a friction surfaceassociated with the side walls of the. followers, a bar extendingtransversely through each follower, and springs interposed between theprojecting end portions of the bars. l

4. In a draft gear, in combination, a pair of chambered followers, acentral two-faced wedge associated with each follower, friction shoeshaving wedging faces cooperating with each face of each wedge, a groupof intercalatingl friction platesinterposed between the shoes at eachrside of the gear and a friction surface associated with the side wallsof the followers, a bar extending transversely through each follower,springs interposed between the projecting end portions of the bars, andVa spring interposed between the shoes at each end of the gear.

5. In a draft gear, in combination, a pair of opposed chambered casings,two groups of intercalating friction plates housed within the casings,wedging means interposed between the two groups of plates, a pair ofbars extending transversely through the casings and engageable with theWedge moons to hold the elements thm-sof in cooperativo relation7compressiioo springe; interposed between the end portions of the twobars, and means acting in opposition-to the springs to spiad the wedges.

6. In adraft gezin' in Combination, a pair of chambered casings,friction elements cooperating with the Side and end Walls they@- l o'damento Yfor compressing the 'friction e ments and comprising imextension )io`}'octing through the end Woll of @zich owing; moansengagea'blo with Suf'h extensions for spreading th@ Wodpes, and moansfor restoring 'the parts to normal. condition after oomgiession.

TWLTER H. CGTTN,

